When a toner cartridge for a laser printer is installed in a printer, a variety of mechanical and electrical connections can be made between the toner cartridge and the printer. Among the connections is a driving mechanical connection between a drive gear on the printer and a driven gear provided on one end of a toner drum in the toner cartridge. Different makes and models of printers can include mechanical and electrical connections in different configurations. For example, one line of printers utilizes a toner drum gear having a twisted, substantially triangular hole formed therein. For proper operation of aftermarket or replacement toner cartridges in that line of printers, the toner drum of the replacement toner cartridge should include a projection that is able to receive driving rotatable force from the twisted triangular hole provided in the toner drum drive gear of the printer.